Dechen Thurman and sister Uma Thurman at the opening party for Jivamukti Yoga Center in Union Square in 2006. Yuki Tanaka/LFI

Uma Thurman’s yoga-teacher brother Dechen Thurman is an alleged “sex addict” who has slept with many of his students at the hip Jivamukti Yoga School in Manhattan, according to a bombshell claim.

While Uma is about to star in the upcoming movie “Nymphomaniac,” some lurid claims are being made about the sex life of her younger brother and his multiple affairs with students.

According to a posting on yoganonymous.com, Dechen — who teaches around nine classes a week at the Union Square center — admitted, “Sometimes there are as many as five or six women in the class who I have slept with,” and adds more students are in love with him.

The claim was posted by Columbia media law adjunct professor Maria Sliwa — a former NYPD officer, publicist, and younger sister of Guardian Angels founder Curtis Sliwa — who has branded Thurman a “yoga gigolo.”

She tells us, “I was a close friend of Dechen and he told me he suffers from sex addiction. He is a good teacher but he has problems with women and his technique is unfortunately very hands-on. It is unsafe for the students. He needs therapy.”

Sliwa, a former student of Thurman, said that, while they’ve never slept together, she has formally complained to the school and submitted a 41-page dossier about him which includes e-mails from him about his sexual conduct and issues with his father, Robert Thurman, a Columbia University Buddhist scholar.

Sliwa concludes, “Yoga class is not a pick-up place for predators.”

Jivamukti school managing director Carlos Menjivar responded by e-mail to Sliwa: “These are very serious allegations which the school takes very seriously . . . we will handle it with the outmost care and seriousness.” But Sliwa says no action has been taken and “The whole thing has been swept under the carpet.”

Jivamukti, co-founded by Sharon Gannon and David Life, boasts celebrity supporters including Madonna, Donna Karan, Sting and Elizabeth Berkley. A school rep declined to comment.

Dechen Thurman’s attorney Steven Machat said, “You have to question what Maria Sliwa’s motive is in coming forward with these claims. Nobody else has complained about Dechen overstepping boundaries. He is a gentleman.”